Displaying publications 41 - 53 of 53 in total

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  1. Usman A, Razak IA, Chantrapromma S, Ghorai SK, Mal D, Fun HK, et al.
    Acta Crystallogr C, 2001 Sep;57(Pt 9):1118-9.
    PMID: 11588390
    The title compound, C(19)H(16)O, crystallizes with two molecules of opposite chirality in the asymmetric unit. In both molecules, the naphthalene and cyclopentanone moieties are individually planar. The two cyclopentane rings adopt envelope conformations, while the cyclohexane ring adopts a boat conformation.
  2. Usman A, Razak IA, Chantrapromma S, Fun HK, Sarkar TK, Basak S, et al.
    Acta Crystallogr C, 2001 Sep;57(Pt 9):1116-7.
    PMID: 11588389
    In the title compound, C(16)H(19)ClN(2)O(4), the pyridine ring is nearly planar, the piperidine ring is non-planar and the cyclohexane ring adopts a screw-boat conformation. The carboxylate group makes a dihedral angle of 80.9 (2) degrees with the least-squares plane through the cyclohexane ring.
  3. Usman A, Razak IA, Chantrapromma S, Fun HK, Philip V, Sreekanth A, et al.
    Acta Crystallogr C, 2002 Nov;58(Pt 11):o652-4.
    PMID: 12415171
    The title compound, C(16)H(17)N(5)S, is in the thione form and crystallizes with two independent molecules in the asymmetric unit. In both molecules, the pentamethyleneimine five-membered ring adopts an envelope conformation, and in one of the molecules this ring shows positional disorder. The thione S and hydrazine N atoms are in the Z configuration with respect to the C-N bond.
  4. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 Apr;58(Pt 4):O239-41.
    PMID: 11932554
    The crystal of the title compound, C(20)H(17)NO(4), which was used for collecting intensity data was twinned. Each of the two crystallographically independent molecules in the asymmetric unit has a planar indole moiety perpendicular to a planar oxopropyl moiety. The distribution of the bonds at the central C atom joining the oxopropyl, phenyl and indole substituents is also planar. The packing is stabilized by intermolecular C-H* * *O interactions, as well as by dipole-dipole and van der Waals interactions.
  5. Usman A, Razak IA, Chantrapromma S, Fun HK, Ray JK, Das Adhikari S, et al.
    Acta Crystallogr C, 2001 Dec;57(Pt 12):1441-2.
    PMID: 11740111
    In the title compound, C20H20FNO5S, the pyrrolidine ring adopts an envelope conformation. The fluorophenyl and thiophene rings are individually planar. The molecular and crystal structures are stabilized by intra- and intermolecular C-H...O interactions.
  6. Usman A, Fun HK, Chantrapromma S, Zhu HL, Wang XJ
    Acta Crystallogr C, 2003 Mar;59(Pt 3):m97-9.
    PMID: 12711770
    In the ternary title compound, catena-poly[[silver(I)-mu-ethylenediamine-kappa(2)N:N'] 3-nitrobenzoate monohydrate], [[Ag(C(2)H(8)N(2))](C(7)H(4)NO(4)) x H(2)O](n), the Ag atom is bicoordinated in a linear configuration by two different N atoms from two symmetry-related ethylenediamine ligands, thus giving linear polymeric chains with an [-Ag-N-C-C-N-](n) backbone running parallel to the a axis. In the crystal packing, these linear chains are interconnected by N-H...O and O-H...O hydrogen bonds to form layers parallel to the ab plane.
  7. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhao BG, Xu JH
    Acta Crystallogr C, 2002 Jan;58(Pt 1):o24-5.
    PMID: 11781485
    In the title compound, C20H16N2O5, both of the 1-acetylisatin (1-acetyl-1H-indole-2,3-dione) moieties are planar and form a dihedral angle of 74.1 (1) degrees. Weak intermolecular hydrogen bonds and C-H...pi interactions stabilize the packing in the crystal.
  8. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 May;58(Pt 5):o287-8.
    PMID: 11983994
    In the title compound, C(18)H(13)BrClNO(3), the heterocyclic ring of the indole is distorted from planarity towards an envelope conformation. The orientations of the indole, oxetane, chloro and bromophenyl substituents are conditioned by the sp(3) states of the spiro-junction and the Cl-attached C atoms.
  9. Chantrapromma S, Kaewmanee N, Boonnak N, Chantrapromma K, Ghabbour HA, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Jun 1;71(Pt 6):571-3.
    PMID: 26090124 DOI: 10.1107/S2056989015008348
    The title aza-stilbene derivative, C14H13NO2 {systematic name: (E)-2-[(4-meth-oxy-benzyl-idene)amino]-phenol}, is a product of the condensation reaction between 4-meth-oxy-benzaldehyde and 2-amino-phenol. The mol-ecule adopts an E conformation with respect to the azomethine C=N bond and is almost planar, the dihedral angle between the two substituted benzene rings being 3.29 (4)°. The meth-oxy group is coplanar with the benzene ring to which it is attached, the Cmeth-yl-O-C-C torsion angle being -1.14 (12)°. There is an intra-molecular O-H⋯N hydrogen bond generating an S(5) ring motif. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming zigzag chains along [10-1]. The chains are linked via C-H⋯π inter-actions, forming a three-dimensional structure.
  10. Chantrapromma S, Kwong HC, Prachumrat P, Kobkeatthawin T, Chia TS, Quah CK
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1280-1283.
    PMID: 31417807 DOI: 10.1107/S2056989019010442
    In the title benzohydrazide derivative, C14H12N2O4, the azomethine C=N double bond has an E configuration. The hydrazide connecting bridge, (C=O)-(NH)-N=(CH), is nearly planar with C-C-N-N and C-N-N=C torsion angles of -177.33 (10) and -174.98 (12)°, respectively. The 4-hy-droxy-phenyl and 3,4-di-hydroxy-phenyl rings are slightly twisted, making a dihedral angle of 9.18 (6)°. In the crystal, mol-ecules are connected by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network, while further consolidated via π-π inter-actions [centroid-centroid distances = 3.6480 (8) and 3.7607 (8) Å]. The conformation is compared to those of related benzyl-idene-4-hy-droxy-benzohydrazide derivatives.
  11. Kwong HC, Sim AJ, Chidan Kumar CS, Quah CK, Chantrapromma S, Naveen S, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Jun 01;74(Pt 6):835-839.
    PMID: 29951241 DOI: 10.1107/S2056989018007429
    In the bis-chalcone mol-ecule of the title compound, C24H18O4·2C3H7NO, the central benzene and terminal hy-droxy-phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis-chalcone and solvate mol-ecules are inter-connected via O-H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (Ff) is 0.18.
  12. Tajuddin AM, Bahron H, Hanafiah RM, Ibrahim N, Fun HK, Chantrapromma S
    Acta Crystallogr Sect E Struct Rep Online, 2014 Oct 01;70(Pt 10):252-5.
    PMID: 25484666 DOI: 10.1107/S1600536814020546
    The asymmetric unit of the title complex, [Ni(C14H11FNO)2], contains one-half of the mol-ecule with the Ni(II) cation lying on an inversion centre coordinated by a bidentate Schiff base anion. The cationic Ni(II) center is in a distorted square-planar coordination environment chelated by the imine N and phenolate O donor atoms of the two Schiff base ligands. The N and O donor atoms of the two ligands are mutually trans with Ni-N and Ni-O bond lengths of 1.9242 (10) and 1.8336 (9) Å, respectively. The fluoro-phenyl ring is almost orthogonal to the coordination plane and makes a dihedral angle of 82.98 (7)° with the phenolate ring. In the crystal, mol-ecules are linked into screw chains by weak C-H⋯F hydrogen bonds. Additional C-H⋯π contacts arrange the mol-ecules into sheets parallel to the ac plane.
  13. Fun HK, Hao Q, Wu J, Yang X, Lu L, Wang X, et al.
    Acta Crystallogr C, 2002 Feb;58(Pt 2):m87-8.
    PMID: 11828089
    In the structure of the title compound, [Cu(II)(en)(2)][(EtO)(2)P(S)S](2) (en is ethylenediamine) or [Cu(C(2)H(8)N(2))(2)](C(4)H(10)O(2)PS(2))(2), the Cu atom lies on a center of inversion and is coordinated in a slightly distorted square coordination geometry by four N atoms from two ethylenediamine molecules. The diethyl dithiophosphate moieties, (EtO)(2)P(S)S(-), act as counter-anions.
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